添加合成注解;

hutool-core/src/test/java/cn/hutool/core/annotation/SyntheticAnnotationTest.java

@@ -0,0 +1,81 @@
+package cn.hutool.core.annotation;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.lang.annotation.*;
+import java.util.Map;
+
+/**
+ * 合成注解{@link SyntheticAnnotation}的测试用例
+ *
+ * @author huangchengxing
+ */
+public class SyntheticAnnotationTest {
+
+	@Test
+	public void testSynthesisAnnotation() {
+		ChildAnnotation rootAnnotation = AnnotatedClass.class.getAnnotation(ChildAnnotation.class);
+		SyntheticAnnotation<ChildAnnotation> syntheticAnnotation = SyntheticAnnotation.of(rootAnnotation);
+		Assert.assertEquals(syntheticAnnotation.getSource(), rootAnnotation);
+		Assert.assertEquals(syntheticAnnotation.annotationType(), rootAnnotation.annotationType());
+		Assert.assertEquals(1, syntheticAnnotation.getDeclaredAnnotations().length);
+		Assert.assertEquals(syntheticAnnotation.getDeclaredAnnotations()[0], rootAnnotation);
+		Assert.assertEquals(3, syntheticAnnotation.getAnnotations().length);
+
+		Assert.assertEquals(syntheticAnnotation.getAttribute("childValue"), "Child!");
+		Assert.assertEquals(syntheticAnnotation.getAttribute("childValueAlias"), "Child!");
+		Assert.assertEquals(syntheticAnnotation.getAttribute("parentValue"), "Child's Parent!");
+		Assert.assertEquals(syntheticAnnotation.getAttribute("grandParentValue"), "Child's GrandParent!");
+
+		Map<Class<? extends Annotation>, SyntheticAnnotation.MetaAnnotation> annotationMap = syntheticAnnotation.getMetaAnnotationMap();
+		ChildAnnotation childAnnotation = syntheticAnnotation.getAnnotation(ChildAnnotation.class);
+		Assert.assertTrue(syntheticAnnotation.isAnnotationPresent(ChildAnnotation.class));
+		Assert.assertNotNull(childAnnotation);
+		Assert.assertEquals(childAnnotation.childValue(), "Child!");
+		Assert.assertEquals(childAnnotation.childValueAlias(), "Child!");
+		Assert.assertEquals(annotationMap, SyntheticAnnotation.of(childAnnotation).getMetaAnnotationMap());
+
+		ParentAnnotation parentAnnotation = syntheticAnnotation.getAnnotation(ParentAnnotation.class);
+		Assert.assertTrue(syntheticAnnotation.isAnnotationPresent(ParentAnnotation.class));
+		Assert.assertNotNull(parentAnnotation);
+		Assert.assertEquals(parentAnnotation.parentValue(), "Child's Parent!");
+		Assert.assertEquals(annotationMap, SyntheticAnnotation.of(parentAnnotation).getMetaAnnotationMap());
+
+		GrandParentAnnotation grandParentAnnotation = syntheticAnnotation.getAnnotation(GrandParentAnnotation.class);
+		Assert.assertTrue(syntheticAnnotation.isAnnotationPresent(GrandParentAnnotation.class));
+		Assert.assertNotNull(grandParentAnnotation);
+		Assert.assertEquals(grandParentAnnotation.grandParentValue(), "Child's GrandParent!");
+		Assert.assertEquals(annotationMap, SyntheticAnnotation.of(grandParentAnnotation).getMetaAnnotationMap());
+	}
+
+	// 注解结构如下：
+	// AnnotatedClass -> @ChildAnnotation -> @ParentAnnotation -> @GrandParentAnnotation
+	//                                    -> @GrandParentAnnotation
+	@ChildAnnotation(childValueAlias = "Child!")
+	class AnnotatedClass {}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target({ ElementType.ANNOTATION_TYPE })
+	@interface GrandParentAnnotation {
+		String grandParentValue() default "";
+	}
+
+	@GrandParentAnnotation(grandParentValue = "Parent's GrandParent!") // 覆盖元注解@GrandParentAnnotation的属性
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target({ ElementType.TYPE })
+	@interface ParentAnnotation {
+		String parentValue() default "";
+	}
+
+	@GrandParentAnnotation(grandParentValue = "Child's GrandParent!") // 重复的元注解，靠近根注解的优先级高
+	@ParentAnnotation(parentValue = "Child's Parent!") // 覆盖元注解@ParentAnnotation的属性
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target({ ElementType.METHOD, ElementType.TYPE })
+	@interface ChildAnnotation {
+		String childValueAlias() default "";
+		@Alias("childValueAlias")
+		String childValue() default "";
+	}
+
+}